Spray head



1929. e. A. MUELLER 1,735,356

Filed Aug. 13, 1925 grmntoz 5%., Way? ploy two separable concentric nozz'le memlnercial machine practice to produce the parts of such apparatus.

Patented Nov. 19., 1929 UNITED STATES PATENT: OFFICE GODFREY A. MUELLER, OI POINT PLACE, OHIO, ASSIGNOR TO THE DE VILBISS GO H- IANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO srnAY HEAD Application filed August 1a, 1925. Serial m. 49,947.

This invention relates to spraying appa- The object of the invention is the provision ratus of the character commonl used in the in a spray-head of the. class described of spraying of paints, varnishes, acquers, and. means for effecting a positive and automatic other surface coating materials, and relates centering of the discharge orifices of the two particularly to the spray-head construction members when they are clamped or drawn Apparatus of this character usually em-, as to make it easily possible'in ordinary comers, one for the material being sprayed and within practical tolerances, and at the same one for the atomizing fluid, and in securing time eliminate the possibility of slight errors these nozzles together in operative spraying in machmlng disturbin the concentricity relation itis extremely important that the of the two nozzle mem ers and absolutely discharge orifices thereof be and remain in preventing leakage of the \atomizing fluid true concentric relation, as otherwise an imfrom the joints between the various parts of proper atomizing of the discharged material the spray-head. p v is obtained. The invention is fully described in the fol- In the construction of spray heads atlowing specification, and one embodimenttogether in assembled relation, in such a way tempts have heretofore been made to obtain thereof illustrated in the accompanying and retain this concentric relation between drawings, in which.:

the nozzle members by conicallyseating one Figure 1 is a central lon itudinal section nozzle member on the other, as in Patent No. of the spray-head portion 0 a spray gun em- 1,613,58 8, dated J anuary- 4, 1927, and also bodying the invention; Fig. 2 is a similar providing a straight outer cylindrical surface view thereof with the inner and outer n zzle on the inner nozzle fitting a'bore in the outer members separated and with parts in full; nozzle as in patent to Holten No. 1,474,324, Fig. 3' is an outer end view of t e spray-head dated Nov. 13, 1923. with the outer nozzle member removed, and

These methods are theoretically correct Fig. 4 is a section on the line 4-4 in Fig. 1.

and if the various parts are made with per- Referring to the drawings, 1 designates fect accuracy the object sought is attained. the barrel or spray-head carr ing portion of However, in commercial manufacturing a spray gun, which is provi ed at its outer practice it is impossible to make the parts inend with a large bore 2 in communication at volved with suflicient accuracy anduniformits inner end, in the present instance, through it t bt i th t i it d i d d a series of small passages 3 with a source of provide for complete interchangeabilty of r pressure supply- .'A bore 4, Which is parts for repair and re lacement purposes. smaller than the bore 2, leads centrally from In all methods hereto ore employed in the h bottom f the bore 2 and has communicaattempt to obtain perfect concentric relation i n wi h a s urcev of supply of paint or other between the two nozzles, one nozzle is fitted rial to be'sprayed, as well understood-in to the other in such a manner that when the the art. two nozzles are separately clamped, or other- A plug 5 is threaded into the bore 2 0f h wise attached to the body of the spray-head, barrel 1 and is provided at its inner end with the sli htest error in machinin the parts a reduced extension 6, which has a close even within practical commercia tolerances conical seat 7 at its outer end in the outer will either disturb the concentricity of the marginal end wall of the barrel bore 4. The nozzle orifices or result in leakage of the. outer end portion of the plug 5 is reduced to atomizing' fluid around the threadsof the form the inner nozzle 8 of the spray-head, clamping means or between the nozzle memsuch nozzle having its outer end, in the presber-and the clamping means, or between the ent instance, of conical formand terminating nozzle member and the body of the sprayat its apex in a tip 9 concentric with the plug gun to which it is attached.

axis.- The nozzle 8 and its tip 9 has adischarge orifice 10 provided axially therethrough such orifice conically enlarging a distance inwardly from its discharge end and opening into an enlarged bore or axial passageway 11 in the plug, which opens at its rear end into the bore 4. 12 designates a valve stem which projects axially through and is smaller in diameter than the bores 4 and 11 and has its forward end forming a conical valve 13, which seats in the conical portion of the orifice 10 and terminates at its forward end in a tip 14 that is adapted to project into and through the reduced discharge end of said orifice when the valve is seated. The tip 14 serves as a cleaning member for the discharge orifice.

The plug 5 at the rear of the nozzle 8 is provided with an annular flange 5 having a straight face at its rear side and being annu= larly undercut at its forward side to form an annular tapering or conical seat 15, which tapers inwardly and rearwardly from adjacent to the outer edge of the flange. The flange 5 extends radially beyond the peripheral portion of the barrel 1 and is adapted to seat against the end of thebarrel through an interposed gasket 16. The outer nozzle 17 of the spray-head is substantially cup-shape in form and is adapted to fit over and around the inner nozzle 8 in spaced relation thereto and to seat at its rear edge against the conical surface 15 of the flange 5. The nozzle 17 is held closely to its seat against the flange 5 by a union nut 18, which threads onto the cylindrical portion of the outer nozzle and has an internal flange at its inner end which engages the rear side of the flange 5 so that a tightening of the nut will draw the nozzle 17 closely to the seat against said flange.

The discharge orifice 19 of the outer nozzle 17 has its axis coincidentwith the axis of such nozzle and is of a size, in the present instance, to permitthe projection of the inner nozzle tip 9 therethrough and to provide an annular air discharge space therearound from the air chamber 20 provided between the inner and outer nozzles. This air chamber has communication with the inner end portion of the bore 2 through a plurality of passages 21 provided lengthwise through the large portion of the plug 5. The projections 22 on the face of the outer nozzle 17 are provided with angled air discharge passages 23 in communication at their inner ends with the air chamber 20 and having their outer ends arranged to direct the streams of air against the stream of combined air and material being discharged from the orifices 10 and 19 of the spray-head nozzles to effect a flattening of such stream, as well understood in the art.

members 8 and 17 together in assembled relation that the discharge orifices of the two shallaccurately align or be truly concentric, as hereinafter more particularly described, as otherwise more air will be permitted to discharge from one side of the orifice 19 of the outer nozzle than from the other side thereof and prevent a proper atomization of the material being sprayed and a properly balanced spray. In the use of most spray guns, especially those equipped with the fan spray feature, it is necessary to frequently loosen the outer nozzle with respect to the inner nozzle, so that a rotary adustment of one relative to the other may be 0 tained, and then to again clamp or secure the two nozzle members in rigid relation. In doing this, considerable difiic-ulty is experienced in causing an accurate registering of the discharge orifices of the two nozzles when clamping the same together, and the primary purpose of the present invention is to provide simple means for automatically accomplishing such accurate aligning of the orifices of the two nozzle members when clamping the same together, regardless of ordinary machining errors found in manufacturing practice and-of commercial tolerances in the dimensions of the various parts of the spray-head. This is accomplished by curving the annular end surface of the nozzle 17 which coacts with the tapered seat 15 toform a portion of the surface of a sphere, the center of which falls at a point in the axis of the'inner nozzle 8 which is approximately intersected by a line a r-a drawn across the face portion of the nozzle 17 which is marginal to its orifice 19.

' This permits the outer nozzle 17 ,by'reason of its ball or spherical seating surface, to

automatically adjust itself to a line seat on the tapered surface 15 of the inner nozzle 8 when the two nozzles are drawn together by the union clamping nut 18; so that the nut 18 will always bear uniformly all around against the flange 5 regardless of small errors of misalignment of the various parts. It is obvious also that such small errors or tolerances in machining the parts will not disturb the practically perfect concentricity of the nozzle orifices at 19, as any movement of the rear end portion of the. nozzle 17 side- Wise on the seat 15 will simply cause such rear end portion to revolve in the arc of a circle around-the centerlocated at the intersection.

of the inner nozzle axis and the line a a. It is also obvious that such movement of the nozzle 17 on the seat 15 of flange 5 incident to obtaining a perfect seating between the two parts will not cause a leakage. between them, as the contact between the two parts will always within limits be a line contact in cir cular form. 7

It is evident that I have provided a simple and efficient form of spray-head having 1nner and outer nozzles which form between them, when clamped together in operative relation, an orifice for the atomizing fluidalways concentric with the material orifice of the inner nozzle regardless of small machining errors and tolerances of these parts or other related parts of the spray-head' I wish it understood that my invention is not limited to; any specific construction, arrangement or form of the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a spray-head, the combination of two nozzles having respectively an inner discharge orifice and an outer discharge orifice surrounding said inner orifice, a seat fixed with respect to one nozzle and against which the other nozzle seats, and means for clamping the two nozzles, the co-engaging portions of said seat and the coacting nozzle being formed one with a conical surface and the other with a spherical surface having its center coincident with the center of the outer end of its orifice, whereby said orifices will automatically assume a concentric relation when the two nozzles are clamped together, regardless of any minor divergence between the axes of the two nozzles.

2. In a spray-head, the combination of two nozzles having respectively an inner 'discharge orifice andan outer discharge orifice surrounding said inner'orifice', a seat' fixed with respect to one nozzle and against which the other nozzle seats, and means for clamping the two nozzles together, the co-engaging' portions of said seat and the coacting nozzle eing formed with surfaces forming a substantially universal joint, whereby said orifices will automatically assume a concentric relation, when the two nozzles are clamped formed in said nozzle,

together, regardless of any minor divergence between the axes of the two nozzles.

3. In a s ray-head, a nozzle having a dis- I charge ori ce, a shoulder fixed with respect to said nozzle and extending outwardly therefrom, a substantially conical seat formed in said shoulder, a second nozzlehaving a 'discharge orifice surrounding the orifice in the first named nozzle and having a part formed to engage the conical seat of the first named nozzle, and means extending beneath the shoulder and engaging the second nozzle for clamping the nozzles together, said engaging portionsof the nozzles forming a substantially universal joint, whereby said orifice will automatically assume a concentric relation when the two nozzles are secured together regardless of any minor divergence between the axes of the two nozzles.

4. In a spray-head, a nozzle having a discharge orifice, a substantially conical seat a second nozzle having a discharge orifice surrounding the orificein the first named nozzle and having a part formed to engage the seat in the first named with respect to one nozzle and against which the other nozzle seats, and means for clamping the two nozzles together, the co-engaging portions of said seat and the co-acting nozzle being formed one with a conical surface and the other with a surface of arcuate form thearc being struck from a point adjacent to the discharge ends of the nozzles whereby to form a substantially universal joint so that the orifices automatically assume a concentric relation when the nozzles are clamped together, regardless of any minor divergence between the axesofthe two nozzles.

In' testimony whereof, I have hereunto signed my name to this specification.

GODFREY A. MUELLER. 

